1. Field of the Invention
The present invention relates to a servo control system with a function for compensating the position of a driven member which is driven by power of a servo motor.
2. Description of the Related Art
A servo control system is known from the past, which compensates a position command value of a servo motor which operates in accordance with the position command value so as to raise the positional precision of a driven member which is driven by the servo motor. For example, the system which is described in Japanese Patent Publication No. 3621278 (JP3621278B) multiplies the torque command value which corresponds to the torque which the servo motor generates, that is, the total torque command value determined by adding the feedback torque command value and the feedforward torque command value, with a predetermined constant, and adds this multiplied signal with the position command value so as to compensate the position command value.
The system described in JP3621278B multiplies the torque of the servo motor (total torque command value) with the constant to compensate the position command value, and does not consider the disturbance between the servo motor and the driven member (frictional force, etc.). Therefore, when the disturbance greatly changes, it is difficult to precisely compensate the position command value.